Electronics · Capacitors and coils / Principles and inquiry
RC charging and discharging experiment guide
Watch the voltage change gradually in a resistor-capacitor circuit. Measure the voltage at one time constant.
How does it work?
At t = τ, charging reaches about 63.2% of the source voltage and discharging about 36.8%.
Key relationship
τ = RC · Vcharge = V₀(1 − exp(−t/τ)) · Vdischarge = V₀exp(−t/τ)
Try this investigation
- Switch between charging and discharging and read time and capacitor voltage together.
- Run and record each of the three baseline presets.
- Double only R, then examine the time constant in discharging mode.
Interpreting your results
With R=10 kΩ and C=100 μF, what is the time constant after changing only R to 20 kΩ?
2 s
Assumptions and limitations
The source, resistor and capacitor are ideal. Leakage and parasitic effects are omitted. Discharging starts from V₀. The scene uses an analytical solution; engine checks use backward Euler. Use this simulation; do not reproduce it with real power supplies or wall outlets.